Effect of grassland degradation on soil aggregate size distribution and stability in Inner Mongolia of China

Grassland degradation is commonly associated with changes in soil structure, yet variability in soil structure has rarely been studied in grassland ecosystems. Soil aggregation is a key indicator of soil structure and is correlated with erodibility and water infiltration capacity. The objective of this study was to investigate the influences of grassland degradation on soil aggregate properties in Inner Mongolia, China. R 0.25 , MWD, WSAP and D were determined to characterize the size distribution of soil aggregates and their stability. Grassland degradation resulted in the breakdown of soil aggregates and decreased soil aggregate stability. R 0.25 , MWD, WSAP and D tended to decrease with progressing grassland degradation. A negative and high correlation existed between soil bulk density and the evaluation indexes (R 0.25 , MWD, WSAP and D) of soil aggregate stability. There was also a strong positive correlation between soil organic carbon content and the evaluation indexes. Our findings are in agreement with the notion that soil bulk density and soil organic carbon are the primary factors influencing the size and stability of aggregates.